I have a joke for you: how are iPhone applications and rap artists Salt-n-Pepa different? Answer: Salt-n-Pepa may be able to "Push It," but iPhone applications can't, thanks to Apple's decision to leave push notifications out of the iPhone 2.1 release. Originally, senior vice president of iPhone software Scott Forstall said that the feature would be done by September, but now that it's October, publications like Macworld are reminding Apple that it has missed the target date.